A vehicle seat H-point defines the hip pivot point or hip pivot axis of the driver or passenger seated in the vehicle seat at a predetermined fore and aft track adjusted position and seat back angle. The vehicle H-point is required for design of a multitude of interior vehicle components including dash and instrument controls, steering and signal controls, foot pedal controls, etc. Therefore, it is crucial that the vehicle seat design meets the required H-point coordinates.
Generally, the required H-point is given in an x and y-coordinate as dictated by the vehicle manufacturer. The vehicle seat must be designed to meet these predetermined H-point coordinates. Such factors as the vehicle seat tracks and risers, seatback angle, foam stiffness, and seat contour, each play a contributing factor in altering the H-point of the vehicle seat. Therefore, each seat design must be tested and the vehicle seat H-point coordinates measured to determine whether the design, or test, seat H-point corresponds with the predetermined H-point coordinates designated by the vehicle manufacturer.
Referring to FIGS. 1 and 2, the prior art method and apparatus for locating and measuring the vehicle seat H-point, as generally known in the vehicle seat manufacturing industry and as currently practiced by the applicant, is shown. FIG. 1 discloses a vehicle seat mounted to a seat riser and supported on a support platform commonly referred to as a buck or throne. The support platform includes an adjustable heel support plate and an alignment pickup bar. The heel support plate pivots about a pivot point on the support platform indicated as the heel point or "HP". The pickup bar is spaced at a predetermined distance from the heel point and the riser of the vehicle seat is firmly abutted against the pickup bar. A seat occupant simulator or manikin is seated on the vehicle seat. The manikin includes a pair of legs and feet which are supported on the heel support plate, a lower trunk portion supported on the vehicle seat, and an upper torso portion pivotally connected to the lower trunk portion by a pivot simulating the seat occupant's hip joint, and therefore, defining the vehicle seat hip pivot axis, or H-point.
The prior art apparatus utilized to locate and measure the vehicle seat H-point is generally indicated at 200 in FIGS. 1 and 2. The apparatus 200 is a generally U-shaped member having a main beam 202 with a leveling indicator 204 positioned in the center thereof. The apparatus 200 includes a reference beam 206 coupled by any suitable bracket to one end of the main beam 202, and a locator beam 208 coupled by a similar bracket to the opposite end of the main beam 202.
In use, the measuring apparatus 200 is positioned so that the distal end of the reference beam 206 is aligned with the center of the pickup bar on the support platform. The distal end of the locator beam 208 includes an aperture 210 for alignment with the hip pivot axis of the vehicle seat manikin. Once the beams 206, 208 are properly positioned, the main beam 202 is leveled and the brackets are tightened to secure the measuring apparatus 200 in a fixed position. The measuring apparatus 200 may then be removed from the vehicle seat and positioned on a scaled drawing sheet as shown in FIG. 2. The drawing sheet includes coordinate lines in the x and y direction which correspond to coordinate grid lines on the support structure of FIG. 1. An image of the vehicle seat is indicated on the drawing as well as the predetermined heel point and pickup bar point taken from the support structure. The predetermined vehicle manufacturer H-point having an x and y-coordinate is marked at its proper location on the drawing as indicated at H-PT. The measuring apparatus 200 is placed on the drawing with the distal end of the reference beam 206 placed on the pickup bar point. A common draftsman's triangle is used to level the apparatus 200 in relation to a coordinate line on the drawing and the design, or test, seat H-point is marked through the aperture 210 on the indicator beam 208. Finally, if the H-point of the test seat is within a generally one-inch tolerance of the required predetermined H-point, then the test seat meets the manufacturer requirements and may proceed to production.
As can be appreciated, the measuring apparatus requires several adjustments, leveling, and tedious placement on the drawing sheet in order to identify the vehicle test seat H-point coordinates. Therefore, it is desirable to provide a method and apparatus for measuring the coordinates of the vehicle seat hip pivot axis while in position and secured on the support platform.
Various apparatuses have been developed for measuring different contours and points of a work piece via x, z and y-axes. For example, the U.S. Pat. No. 4,133,112 to Matthiessen discloses an apparatus for measuring a work piece including a rectangular support frame having a guide rail with the measuring scale extending the entire length of the support frame. A guide carriage carrying a measuring device is received on the guide rail. The measuring device includes a column inserted in the guide cartridge and a receiving part wherein a measuring rod is disposed to be longitudinally displaceable. A measuring feeler is mounted at the distal end of the measuring rod to locate and measure a work piece. However, the measuring apparatus and system does not provide a support structure for supporting a vehicle seat and including x, z and y-coordinate axes to locate and measure the coordinates of a vehicle seat hip pivot axis.